Work support for leather working machines



Sept. 26, 1939. a. A. SCHETTLER WQRK SUPPORT FOR LEATHER WORKINGMACHINES Filed Spt. 7, 1938 u M m m3 0 AB u I #1 w vl K 2 6 "3% 2 7 m/w, 0 l 2 M 2 or 1 1 2 .1 u 2 C+ a a r a 6 w M m 0 d Patented Sept. 26,1939 UNITED STATES PATENT OFFICE Gustav A. Schettler, Leeds, England,assignor to The Turner Tanning Machinery Company,

Portland, Maine, a corporation of Maine Application September 7, InGreat Britain 12 Claims.

This invention relates to machines for per forming operations uponhides, skins and leather. While the invention is illustrated as embodiedin a work support for a machine specially designed 5 to glaze suitablyprepared leather surfaces, it is to be understood that the invention andvarious important features thereof may have other applications and uses.

'10 It is an important feature of the invention that r a bed or othersupport for work pieces, while the latter are being presented to a tool,is arranged to be operated between work receiving and work presentingpositions by a toggle having a spring 1 associated therewith and soarranged that straightening of the toggle places the spring undersuitable stress to support yieldingly the bed or work support againstpressure of the tool on the Work piece. An advantage of thisconstruction resides in the fact that strengthening of a treadleoperated toggle to lift the work support to operative positionautomatically relieves pressure on the toggle in all directions exceptthat in which pressure is exerted thereon by the said spring, therebyrelieving the foot of 3' the operator from the effects of pressure onthe work support exerted by the operating tool.

From another viewpoint the invention includes a single compressiblespring for supporting both ends of a bed or other work supportyieldingly 30 against the pressure of the work treating tool in anarrangement wherein a toggle under control of the operator isstraightened against the resistance of the spring, whereby the spring isproperly tensioned effectively to support the bed or work {35 support atthe same time that straightening of the toggle, at a minimum of efforton the part of the operator, lifts the bed or work support to present awork piece for treatment by said tool.

With these and other important features and 49 advantages in mind, theinvention will now be described in detail and then pointed out moreparticularly in the appended claims.

In the drawing,

Fig. 1 is a side elevation, partly in section, of the lower part of themachine with the work supporting table or bed in a raised position; and

Fig. 2 is a similar View to Fig. 1 but showing the said table or bed ina lowered position.

In the illustrated embodiment of the invention, 50 which is speciallyintended for performing glazing and analogous operations on leather,there is provided a substantially horizontal work supporting table orbed I on the top surface of which is stretched a sheet or blanket 2 ofsuitable material 55 having associated therewith a rotary tensioning1938, Serial No. 228,806 October 1, 1937 7 device, such as 3, adapted tobe held in adjusted position by a weighted pawl as indicated in Fig. 1.The said table or bed is supported in the low-er or base portion of themachine frame, which latter comprises two side frame members such 5 as 4suitably spaced apart by and bolted to members 5 and 6. The frame member5 is disposed at the front of the machine while the member 6 is arrangedto extend across the top of the aforesaid lower or base portion. 10

It is to be understood that only so much of the complete machine isshown as is necessary to illustrate the application thereto of theinvention. In this respect the usual superstructure for supporting themeans for carrying and operating the tool has not been shown, althoughin Fig. l the said tool is represented at 'l, the tool being adapted tooperate with a rapid reciprocatory motion in the directions indicated bythe arrows A and B. As is customary in machines of this type, the toolis adapted to be operated by or from a rotating crank through the mediumof a connection rod, a portion of which is shown at 8.

Suitably attached to the base portion of the frame and arranged one ateach side of the latter are two bracing members such as 9 between whichare supported two bell cranks I0 and H. For the sake of clarity, onlyone of the bracing members 9 is shown in the drawing, but as will be 1understood, the pivot pins l2 and I3 for the bell cranks l0 and II,respectively, extend transversely through and are supported by both ofsaid bracing members. As will be seen, the bell cranks are each arrangedso that one of the arms thereof is substantially horizontally disposedand to the outer ends of these horizontal arms are attached memberswhich serve to support the table or bed I. In the specific example nowbeing described, a single supporting member I which projects downwardlyfrom the under side of the work supporting'table or bed at the front endthereof is connected at its lower end to the outer end of the horizontalarm of the bell crank I0, while two somewhat similar supporting membersprojecting downwardly from the rear end of the said table or bed areconnected to the corresponding arm of the other bell crank ll Thus, aswill be understood, the table or bed is supported at three pointsalthough only one of the rear supporting members-represented at l5isshown in the drawing. In order to provide connections between twomembers [5 and the bell crank II, the latter may have two horizontalarms or a single horizontal arm with a cross piece rigidly ,5

secured to the end thereof and having provision for pivotally supportingthe lower end of each member I5. It is customary in machines of the typeaforesaid to provide some means whereby the work supporting table or bedcan be tilted sideways to a slight extent. This fine adjustment takescare of variations in the thickness dimensions of different batches ofwork and also of differences in the opposite ends of the glass cylindercommonly employed as a glazing tool. To enable such adjustments to beeffected in the present machine one of the rear supporting members suchas that shown at I5 is formed or provided with a screw threaded portionI6 adapted to have engagement with a correspondingly threaded block I'Ipivotally mounted at the outer end of the appropriate arm of the bellcrank II. The member I5 is capable of being rotated by any suitablemeans (not shown) and, by appropriate manipulation of said member, thetable or bed I can be tilted sideways as and when required. A look nutI8 is provided to set the member I5 in any position to which it isadjusted. It will be understood, of course, that the three supportingmembers are so disposed in relation to each other and connected to thetable or bed as to permit the latter being readily tilted in therequired manner.

The substantially vertical arms of the two bell cranks are connectedtogether at their lower ends by means of a tie rod I9. At each end, thesaid rod has a screw thread engagement with a coupling element 29 whichin turn is pivotally mounted on the corresponding bell crank I0 and I I.The elements 20 are adapted to turn on pivot pins 2i and 22 suitablycarried by the bell cranks I9 and II, respectively. One end of the rodI9 is formed with a right-hand and the other end with a left-hand threadand the aforesaid coupling elements are correspondingly threaded so thatby rotating the rod the distance between the pivot pins 2! and 22 isvaried. Since in the construction illustrated the bell crank ID isnormally restrained from movement, as will be hereinafter explained,then by manipulating the rod I9 the bell crank II will be caused to turnon the pivot pin I3 to a slight extent with the result that the rear endof the table or bed I will be raised or lowered to a correspondingextent according to the direction in which the rod is turned. Lock nuts23 are provided in association with the rod I9 to set the bell crank inany desired position. By the means just described it is consequentlypossible to adjust the table or bed in such a way that it can be seteither parallel or in a slightly inclined position with respect to theworking stroke of the tool. In this way provision is made whereby apressure can be applied to the work at one end of the table or bed whichis harder or lighter than the pressure applied at the other end.

In accordance with an important feature of the invention, thesubstantially vertically disposed arm of the bell crank ID is formed orprovided with an extension 24 which is adapted to be acted upon for thepurpose of effecting the raising and lowering movements of the table orbed to bring the work into and out of contact with the tool I. The saidextension constitutes a bearing for the outer end of one of the links 25of a toggle joint, the other link of which is indicated at 26. The outerend of the last-mentioned link is free to swivel in a bearing 21 formedon or secured to a longitudinally slidable bar 28, and the two links 25,26 are suitably connected at their inner ends to a center block 29. Thebar 28 is formed at its rear end with a reduced portion 39 which issupported by and adapted to slide in a suitable bearing 3| in a bracket32 attached to the machine frame. The bar 28, moreover, is disposed atone side of and is unconnected both with the extension 24 and the centerblock 23, which latter is connected by means of an adjustable connectingrod 33 with a double-ended treadle 34.

Conveniently the said treadle is rigidly secured to a short shaft orspindle 35 which is suitably journaled in the machine frame and hasextending therefrom an arm 36 to which the lower end of the rod 33 isconnected. The shaft or spindle 35 has associated therewith a weight 31which serves to counterbalance the combined weight of the table or bedI, the toggle mechanism and the associated connections, so thatwhichever end of the treadle is depressed the latter will remain in thedesired position until again acted upon by the operator of the machine.Ihe arrangement of the parts so far described is such that when the footportion 39 of the treadle is depressed, the rod 33 is moved upwardly tostraighten the toggle links 25 and 26 and consequently to turn the bellcranks I0 and II on their pivot pins in such a direction as to raise thetable or bed I bodily into the position shown in Fig. 1. When the tableor bed is raised to this position, any work piece supported thereon isbrought into contact with the tool I. When now, it is desired to effecta separation of the work from the tool, the foot portion 49 of thetreadle is y depressed with the result that the toggle links are pulleddownwards so that the bell cranks are suitably turned to lower the tableor bed into the position shown in Fig. 2. It will be understood, ofcourse, that the toggle mechanism only acts directly on the bell crankIII and that any turning movement imparted to the latter is transmittedto the bell crank II through the rod I9. In order to prevent the togglelinks from passing the dead center position indicated in Fig. 1 when thefoot portion 39 is depressed, the center block 29 is conveniently formedwith an abutment 4I adapted to come into contact with the under side ofthe rod I9. If desired, the stop or abutment 4! may be so dimensionedthat the toggle cannot be completely straightened. In that case, thetoggle will be broken, upon releasing the treadle 39, by the weight ofthe table without using the treadle 40. The construction, moreover, issuch that when the table or bed is in either of the two positions shown,the bell crank I0 is restrained from movement by the toggle mechanism;consequently when the rod I9 is adjusted in the manner and for thepurpose aforesaid, only the bell crank II is moved.

In the particular embodiment of the invention now being described, thetable or bed I is made yieldable by a single compression spring 42 whichis so arranged as to exert a pull on the bar 28 in the direction of thearrow C in Fig. 1. Conveniently, and as shown, the bar 28 is supportedat the front end thereof by a screw threaded spindle 43 which extendsthrough the frame member 5. The spring 42 surrounds the spindle 43 andabuts at one end against the member 5 and at the other end against anabutment plate or ring 44 on said spindle. On the inside of the baseportion of the frame, the spindle 43 is fitted with an adjustable stopcollar 45 adapted normally to abut against a face 46 provided at theback of the frame member 5 for the purposes of limiting the expansion ofthe spring 42 and determining the position of the said spindle and hencealso of. the bar 28. Provision of any suitable character is preferablymade whereby the pressure exerted by the said spring on the abutmentplate or ring 44 can be varied so as correspondingly to modify theyieldability of the table or bed and thus vary the pressure at which thework is operated upon by the tool. For this purpose it is convenient toprovide a hand Wheel 41, the central boss of which is suitably screwthreaded internally for engagement with a screw threaded portion 43' ofthe spindle 43. The said hand wheel is positioned in front of theabutment plate or ring 44 so that when the wheel is rotated the spring42 is either compressed or permitted to expand according to thedirection of rotation. In this way the compression of the spring can beregulated to achieve the desired result without in any way aiiecting theposition of the table or bed I. Now, as in all machines of the typeconcerned, when the operating tool 1 moves over the table or bed I thelatter is depressed to a slight extent. Whenever the table or bed isdepressed in this way, the bell cranks l and l I are turned in acounterclockwise direction with the result that the bar 28 together withthe spindle 43 are moved longitudinally in the direction of the arrow D(Fig. 1) and this movement causes the stop collar 45 to move away fromthe face 46 and the spring 42 to be compressed. Thus the load of thecompression spring 42 is applied through the table or bed on to the workwith equal force throughout the full length of the operating tool. Asalready explained, by suitable movement of the hand wheel 4'! either ahard or a light pressure can be applied.

As hereinbefore mentioned, the machine is provided with some meanswhereby the table or bed I can be adjusted bodily in relation to thetool. In the example illustrated, a hand wheel 48 is provided foreffecting such an adjustment by raising or lowering the table or bedbodily to the required extent. To enable the desired efiect to beachieved, the spindle 43 is made rotatable in a bearing 49 formed on theframe member and the hand wheel 48 is rigidly secured to the front endof, the said spindle, the other end of the latter being screw threadedfor engagement with a correspondingly screw threaded part 50 formed onor secured to the front end of the bar 28. Thus, by turning the handwheel 48, the bar 28 is caused to move longitudinally in the bearing 3|and, according to the direction of rotation of the hand wheel 48, thetoggle mechanism is operated either to raise or to lower the table orbed I for adjustment purposes. If, at any time, it is desired to make anadjustment of. the table or bed in the manner just described withoutvarying the pressure applied on the work piece by the tool, then boththe hand wheels 47 and 48 are turned together.

In the operation of the machine a tanned skin, such as a suitablyprepared kid or calf skin, is placed by the operator upon a bed I andshifted between strokes of the tool 1, care being taken to see that eachpath of the tool on the surface of the work piece overlaps that of thepreceding stroke of the tool. It isto be understood that at the time ofintroducing the work piece the bed I is in the depressed position shownin Fig. 2 and that ordinarily the tool 1 is in continuous oscillation.The operator throws the work piece over the bed I from one side thereofand, having located it on the bed, he depresses the treadle 39 therebyinitiating treatment of the work piece. At each stroke of the tool thebed yields slightly against the resistance of the spring 42. Suitabletreatment of the work is secured through one or more of the adjustmentsprovided to suit the requirements of. the work piece, particularly as toits thickness dimensions, the degree of firmness of the fiber, and thequality of the finish on the surface.

Having thus described my invention, what I claim as new and'desire tosecure by Letters Patent of the United States is:

1. In a work support for use in leather treating machines, awork-supporting bed, a single compression spring connected to the bed toresist yieldingly downward movement of both ends of the bed, and atoggle mechanism interposed between the work supporting bed and thespring and so arranged that, when the toggle is straightened, the springis put under stress yieldingly to resist downward movement of the bed.

2. In a work support for use in leather treating machines, a worksupporting bed, a treadle operated toggle connected to said bed andmovable under the control of the operator to eifect movement of the bedbetween work receiving and work presenting positions with respect to awork treating tool, and a spring in line with the straightened toggleand arranged to be put under stress upon straightening of the toggle,whereby the bed is yieldingly supported by said spring and tool pressureon the work pieces is transmitted to the spring and not to the treadle.

3. In a work support for use in leather treating machines, a bed, a pairof interconnected bell cranks having connections to support the bed, atoggle connected to one of the bell cranks and arranged to be operatedto effect movement of the bell cranks to lift and to lower the bed, anda manually operable member connected to said toggle alternately tostraighten and to break the toggle, the straightened toggle having theeffect of removing pressure on the bed from said manually operablemember.

4. In a work support for use in leather treating machines, a bed, a pairof interconnected bell cranks having connections to said bed, a spring,connections between the spring and one of the bell cranks to resistyieldingly movement of the bell cranks in one direction, a toggleconnected to one of the bell cranks, and means to straighten the toggleagainst the opposing force of said spring whereby wardly against theresistance of said spring.

5. In a work support for use in leather treating machines, a bed, a pairof interconnected bell cranks having connections to support the bed, amember movably mounted in the frame of the machine, a spring to resistyieldingly movement of said member in one direction, a toggle connectedto said member and to one of the bell cranks, and means to operate thetoggle to straighten the latter thereby moving the bell cranks to liftthe bed, the arrangement being such that downward movement of the bed isresisted yieldingly by said spring.

6. In a work support for use in leather treating machines, a bed, a pairof bell cranks having connections to support the bed, a link connectingsaid bell cranks, a toggle connected to one of the bell cranks, andmeans under control of the operator to operate the toggle, thereby toeffect movement of the bell cranks to lift and to lower the bed.

the bed may yield down- 7. In a work support for use in leather treatingmachines, a bed, a pair of bell cranks having connections to support thebed, a link connecting said bell cranks, a rod slidable in bearings inthe frame of the machine, a spring to resist yieldingly movement of therod in one direction, a toggle connected to said rod and to one of thebell cranks, and means to operate the toggle to straighten the latterthereby moving the bell cranks to lift the bed, the arrangement beingsuch that downward movement of the bed is resisted yieldingly by saidspring.

8. In a work support for use in leather treating machines, a bed, a pairof bell cranks having connections to said bed, a link connecting thebell cranks, a spring, connections between the spring and one of thebell cranks to resist yieldingly movement of the bell cranks in onedirection, a toggle connected to one of the bell cranks, and a treadlehaving connections to straighten the toggle against the pressure of saidspring whereby the bed may yield downwardly against the resistance ofsaid spring.

9. In a work support for use in leather treating machines, a bed, a pairof bell cranks supported in the frame of the machine, each of the bellcranks having a substantially horizontal arm, three members between thebed and the bell cranks arranged to furnish a three-point support forthe bed, two of the three members being arranged between the front endof the bed and the substantially horizontal arm of the adjacent bellcrank, a link connecting the bell cranks, a spring to resist yieldinglymovement of the bell in one direction, and a toggle under the control ofthe operator and arranged to move one of the bell cranks in a directionto place said spring under stress whereby downward movement of the bedis resisted yieldingly by said spring.

10. In a work support for use in leather treating machines, a bed, apair of bell crank members connected to said bed to support the latter,

a link connecting the bell cranks, a spring connected to one of the bellcranks yieldingly to resist downward movement of the bed, and a togglemechanism under the control of the operator to move one of the bellcranks to put the spring under pressure.

11. In a work support for use in leather treating machines, a bed, apair of interconnected bell cranks having connections to support thebed,

a single compression spring connected to one;

bed, and a toggle mechanism interposed between one of the bell cranksand said spring, whereby when the toggle is straightened, the spring isput under suitable compression yieldingly to resist downward movement ofthe bed.

12. In a work support for use in leather treating machines, a bed, apair of bell crank members connected to support and operate a bed, alink connecting said bell crank members, a toggle mechanism connected toone of the bell crank members to operate the latter, and a springconnected to the toggle mechanism to resist yieldingly straightening ofthe toggle and to provide resistance to movement of the bell crankmembers in one direction whereby the bed is yieldingly supported againstdownward movement.

GUSTAV A. SCHETTLER.

